Of course it's not good. "Good" would only get in the way. The new "Transformers" movie sits right on the beam, qualitatively, with the previous three sequels (the first one was a mite less ... I don't know, something). So be warned or be encouraged, depending on your allegiance to the earlier movies.

Of course it'll be profitable. The previous four "Transformers" films made more than $3.7 billion worldwide. It's time to throw another bil on the fire.

"Deep down inside, you begin to wonder: Has my life been wasted?" This is Academy Award-winning Anthony Hopkins talking, as he shovels another steaming load of mythological exposition for the benefit of Mark Wahlberg, who plays the subtitle of this fifth "Transformers" movie: "The Last Knight." Or "Knight of the Living Dead." Or is it "Transformers: Revenge of the Fidget Spinners"? I can't say. The film wiped my memory, my faculties and my windshield clean sometime around minute 40 of its 146 minutes.

I'm not sure how bent up we can get, realistically, about spoilers regarding "Transformers: It Happened One Knight" because director Michael Bay's exercise in extreme BRRAAAAUGGHGGH and KRRRAAANNNGGG and KA-RRRRRRRRUNCH!!! arrives pre-spoiled by the trailers. Hopkins is the most conspicuous newbie to Bay's Hasbro-derived franchise. He plays an eccentric English lord, one of the keepers of the "secret history of Transformers" through the ages.

The earlier movies toyed with this notion of metallic residents of the planet Cybertron and environs, traveling to Earth many years ago, then working undercover in service to humankind. One of the good bots killed Hitler, we're told in the middle of a particularly weird exposition dump.

Optimus Prime, the last movie's noble, sacrificial metal lamb, lands back on his home orb and is immediately turned "bad" by Quintessa, ruler of Cybertron and hater of Earth. The wizened old pro must return to Earth to retrieve the mighty, all-powerful staff of life, hidden for centuries. It spells eternal ever-after for Cybertron and eternal nevermore for Earth. It's one or the other. Either they win, or we win.

Wahlberg returns as the American Joe leader of the resistance; Laura Haddock, latest alum of the Michael Bay School of Haughty, Full-Lipped Females, is the skeptical Oxford professor with an intriguing lineage; Isabela Moner plays a 14-year-old Chicago survivor of the attack on our fair city, taken under the Wahlberg character's wing. For just a minute, in the 5th century sequences, Stanley Tucci yanks a few laughs out of some bizarre line readings calling attention to the fact that nobody else providing comic relief in "Saturday Knight Fever" or whatever it's called is remotely funny. Not even John Turturro. And he tries. Hard.

The script by Art Marcum, Matt Holloway and Ken Nolan zigzags in and out of the revisionist history of King Arthur, a heroic archetype who's having a big movie summer with this film and the earlier "King Arthur: Legend of the Sword." (Bay was supposed to direct that one, which ended up in the mitts of Guy Ritchie.) "Big," in this instance, does not mean, "You should see it." It means simply "large," or "leaden."

"Transformers: Knight at the Museum" skitters nervously from a Dakota Badlands auto junkyard, inhabited by Autobots in hiding, to London to Stonehenge to Havana to Cybertron. Optimus Prime runs into trouble when he's forced to adopt a "Cybertron First" policy of survival. He learns his lesson, and politically this development marks a slight shift toward the center (from the right, that is) for Bay's franchise. Few will notice. The smackdown sequences are especially masochistic, though Bay and cinematographer Jonathan Sela shot most of the picture on IMAX digital cameras, in 3D, so it looks better than the average postproduction 3-D conversion job.

No fewer than six editors receive screen credit for their work here, and I suspect that's why the technical and budgetary bravura comes to so little in "Transformers 5." To paraphrase Irving Berlin paraphrasing Ira Gershwin, it ain't got rhythm. The rhythmic assurance of truly bracing screen action, even if it's just a bunch of metal beating up a bunch of other metal, or clobbering humans, never gains traction. The cross-cutting suggests the editors took care of things via group text.

The thing about Michael Bay is that he has talent, of a sort, and a dogged eye for what sells. He also has a pile-driver sensibility, along with the most heartless brand of "heart" in modern movies. (The makeshift-family pathos in some scenes rivals "The Fate of the Furious" for robotic sentiment.) As for the central conceit of the "Transformers" mythology: I can work up only so much enthusiasm for the idea of Transformers having dictated the course of human history from the Dark Ages onward. On the other hand, that explains why we're on the fifth "Transformers" movie.